Dual-Blade Cutting Device for Silent Towed Sonar Severing

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Solution Overview

Problem

Existing cutting devices for towed sonars in emergency situations are noisy due to explosion-activated mechanisms, which is undesirable in submarine operations where silence is crucial for concealment.

Innovation Solution

A cutting device with two spaced cutters that attempt to cut the towed sonar sequentially, using non-magnetic, corrosion-resistant blades activated by hydraulic cylinders, with sensor feedback for successful cut determination and manual or automatic operation, ensuring silent and reliable cutting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If an explosion-activated cutting blade is used to sever the towed sonar, then the cutting force is sufficient to cut through solid metal coupling elements, but the explosion emits noise which compromises submarine concealment

Engineering Contradiction:
Improvecutting forceVSAvoidnoise
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The cutting device is divided into two separate cutting units arranged at a predetermined distance from each other. Each unit has its own cutting blade and activation mechanism. This segmentation allows the system to attempt cutting with the first unit, and if that fails (blade becomes stuck), the second unit can be activated to complete the cut, providing redundancy while maintaining the ability to cut through tough materials without requiring explosion forces

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent replaces the explosion-activated mechanical system with a hydraulically activated system. Instead of using an explosion to generate the cutting force, hydraulic cylinders are used to drive the cutting blades. This substitution eliminates the noise-generating explosion while providing sufficient controlled force to cut through the towed sonar cable and its coupling elements

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If a single cutting device is used to sever the towed sonar, then the device complexity is reduced, but the reliability of successful cutting is compromised when the blade becomes stuck on an impervious section

Engineering Contradiction:
Improvenumber of cutting devicesVSAvoidcutting success rate
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system performs a preliminary cutting attempt with the first cutting unit before considering the need for the second unit. The cutting blades are positioned and ready to engage the towed sonar cable. This preliminary action allows the system to attempt the cut with the first blade, and only if that blade becomes stuck on an impervious section (such as a solid metal coupling element) does the system proceed to activate the second cutting unit, ensuring reliable completion of the cutting operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent incorporates a backup cutting unit as a form of beforehand cushioning against the failure of the primary cutting unit. By having the second cutting unit ready at a predetermined distance from the first, the system prepares in advance for the possibility that the first blade may become stuck, ensuring that the cutting operation can still be completed successfully without compromising the overall reliability

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The device effectively and silently cuts through towed sonar components, including solid metal elements, by using a secondary cutter if the primary one fails, maintaining operational silence and preventing corrosion, thus ensuring successful separation without noise pollution.

Implementation Method 1

The cutting device comprises a hydraulic cylinder (32) configured to activate the cutting blade (44)

Methodology Applied
Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

The cutting device comprises one or more sensor devices, preferably configured as proximity sensors, which determine the position of the cutting blades and generate a signal based on the acquired data

Methodology Applied
Scientific EffectPosition detection:

Implementation Method 3

the material of the cutting blades is non-magnetic, thus preventing the vessel's position from being determined

Methodology Applied
Scientific EffectNon-magnetic property:

Implementation Method 4

the material of the cutting blades is either corrosion-resistant—for example, bronze—or the cutting blades are embedded in a liquid—preferably oil—to prevent corrosion

Methodology Applied
Scientific EffectCorrosion resistance:

Data Source

PatentEP3544776B1Cutting device and method for cutting the cable of a towing array sonar and
Publication Date: 2020.07.01 ATLAS ELEKTRONIK GMBH
  • EP3544776B1 patent drawingFigure 1~2
  • EP3544776B1 patent drawingFigure 3
  • EP3544776B1 patent drawingFigure 4

AI summary

The invention relates to cutting device (16, 16') having two cutting blades (44) for cutting a towed sonar (10) that comprises sections that cannot be cut through. In order to ensure that the cutting was not unsuccessful because a section (12) of the towed sonar (10) that cannot be cut through was hit by the first cutting apparatus (44), the second cutting apparatus cuts the towed sonar (10) at such a distance that the second cutting apparatus does not hit a section (12) that cannot be cut through. The invention further relates to a corresponding method.